How are extrusive rocks formed?
magma gets trapped inside earth and cools to rock
volcanoes apply force to solid rocks and eject them.
magma gets forced to earth's surface and cools to rock
volcanoes trap lava inside earth, where it cools to rock

It would be Magma gets forced to Earth's surface and cools to rock.

Explanation:

Magma doesn't get "trapped" inside Earth, it latches itself to the Earth's surface and when it reaches to that part of the Earth, it starts cooling down to be describes as an extrusive rock(s).

individual oxygen atoms are formed during photosynthesis.-c.

the diploid number of chromosomes is sometimes represented by the symbol 2n. for the fruit fly, the diploid number is 8, which can be written as 2n = 8, where n represents twice the number of chromosomes in a sperm or egg cell.